Efficient delivery of a nucleic acid to a desired target site has been the focus of many intense studies. Once introduced to the target site, the nucleic acid may exert, directly or indirectly, a biological effect in the target site. In some instances, the delivery of the nucleic acid may take use of carriers that are designed to deliver the nucleic acid to the target site. Exemplary nucleic acids that may be delivered to a target site include deoxyribonucleotides nucleic acid (DNA) and ribonucleotides nucleic acids (RNA), such as, for example, siRNA, miRNA, shRNA, Antisense RNA (AS-RNA), and the like.
For in-vitro or ex-vivo delivery of siRNA to cells, conventional transfection methods are generally used. In-vivo delivery of siRNA can be classified into two groups: localized or systemic. Whereas cellular and local delivery deal with the need for internalization, release, and accumulation of the siRNAs in the cell cytoplasm, systemic delivery in an entire animal enforces additional hurdles such as, for example, the siRNAs interaction with blood components, entrapment within capillaries, uptake by the reticuloendothelial cells, degradation by RNases, anatomical barriers (such as the liver, spleen and filtration by the kidneys), immune stimulation, extravasation from blood vessels to target tissues, permeation within the tissue, and the like.
Various methods and carriers have been suggested for systemic delivery of siRNA molecules. The methods and carriers include passive delivery of the siRNA or targeted delivery of the siRNA. Exemplary carriers described in the art include: Stable nucleic acid-lipid particles (SNALP), neutral liposomes, lipidated glycosaminoglycan particles (Gagomers), lipidoid containing liposomes, Pegylated liposomes, atelocollagen, cholesterol-siRNA, dynamic polyconjugates, PEI nanoplexes, antibody-protamine fusion proteins, aptamer-siRNAs, targeted cationic liposomes and cyclodextrin containing polycation (CDP). (reviewed by Weinstein and Peer (2010), Schroder et al., (2010) and Shim et al. (2013)). For example, a publication by Liu et al. is directed to A Lipid Nanoparticle System Improves siRNA Efficacy in RPE Cells and a Laser-Induced Murine CNV Model. For example, a publication by Shim et al., is directed to application of cationic liposomes for delivery of nucleic acids. For example, PCT patent application publication no. WO 2011/075656 is directed to methods and compositions for delivery of nucleic acids.
Some of the nucleic acid carriers described in the art make use of hyaluronic acid that may be used as component of the particle and/or as a targeting moiety. For example: A publication by Taetz et al., is directed to Hyaluronic acid modified DOTAP/DOPE liposomes for the targeted delivery of anti-telomerase siRNA to CD44 Expressing Lung cancer cells. A publication by Lee. et al. is directed to target specific intracellular delivery of siRNA using degradable hyaluronic acid nanogels. A publication by Choi et al., is directed to self assembled hyaluronic acid nanoparticles for active tumor targeting. A publication by Peer et al., is directed to Systemic Leukocyte-Directed siRNA Delivery Revealing Cyclin D1 as an Anti-Inflammatory Target. For example, a publication by Arpicco et al., is directed to Lipid-Based Nanovectors for Targeting of CD44-Overexpressing Tumor Cells. For example, US Patent application no. US 2002/0012998 is directed to cationic liposomes. For example, PCT patent application publication no. WO 2011/013130 is directed to cell targeting nanoparticles comprising polynucleotide agents and uses thereof. Additionally, U.S. Pat. No. 7,544,374 is directed to lipidated glycosaminoglycan particles and their use in drug and gene delivery for diagnosis and therapy. A publication by Cohen et. al. (2015) is directed to Localized RNAi Therapeutics of Chemo-Resistant Grade IV Glioma using Hyaluronan-Grafted Lipid-Based Nanoparticles.
Nevertheless, the carriers described in the art, including carriers making use of hyaluronic acid do not address all the hurdles associated with a successful delivery of nucleic acids, such as, siRNA to a target cell, and in particular, in-vivo delivery.
There is thus a need in the art for compositions for the efficient and specific delivery of nucleic siRNA into a desired target site, wherein the carrier compositions are stable, have a long shelf life, biodegradable, amenable to industrial production processes, have high encapsulating capacity, non toxic, avoid induction of immune responses, provide enhanced protection (stability and integrity) to the siRNA encapsulated therein and are able to efficiently deliver in-vitro and in-vivo, the siRNA to its target site, such that the siRNA is able to efficiently exert a desired effect.